Modern telephones and telephone switching systems provide a wealth of services or features beyond plain old telephone service ("POTS"). Features such as call hold, call waiting, three-way calling and the like have been available to office and home telephone users for many years. Many offices and homes subscribe to at least one of these features, and often more than one.
As a first step to using features, the user generally places a call on hold. A problem in the art is that a user cannot monitor the call on hold. Not hearing the call on hold often makes the user uncomfortable, or possibly even causes the user to forget about the call. Further, there are often several steps generally involving the switch hook which must be performed to put a call on hold and retrieve it. As a result, these features are not exploited to the fullest potential by the user, even though the user subscribes to these features. Being able to monitor a call on hold, and to put a call on hold with a minimum number of steps, is therefore highly desirable in the art.
In an operator position equipment arrangement disclosed in U.S. Pat. No. 3,294,922, issued to E. W. Schneider et al. on Dec. 27, 1966, an operator has the capability of monitoring one operator position while conversing on another. A headphone set is provided with two receivers that are selectably connectable to "home" and "mate" operator positions, and a transmitter that is connectable to one of the operator positions. The Schneider patent does not, however, disclose an arrangement where the operator moves a first call from one headphone receiver to the other to allow the operator to answer a second call in privacy while continuing to monitor the first call.
In a call-waiting announcement arrangement disclosed in U.S. Pat. No. 4,922,490 issued to J. R. Blakley on May 1, 1990, a calling party's name is announced electronically over a speaker in the telephone station set without disconnecting an established call. The station set is an integrated services digital network (ISDN) speaker phone set connectable to an ISDN switching system via a digital subscriber line having two B-channels and a D-channel. In response to a message transmitted from the switching system on the D-channel, the ISDN speaker phone set connects the speaker to a B-channel and announces call waiting identity information while an established call continues on the other B-channel connected to the handset. The Blakley arrangement does not provide for connection of the second call to the station set so that the two calls are connected simultaneously. The Blakley arrangement further does not provide the capability to change connections readily under the control of the user such that the first call is moved to the speaker and the second call is then connected to the handset so that the user may monitor the first call while conversing privately on the second.
In view of the foregoing, a recognized problem in the art is the absence of a telephone system that allows a customer to conveniently answer a second call in privacy while continuing to monitor a first call.